Now that the Nxt coin shuffling code is released, and set to be enabled on production in two weeks, we will be holding Shuffling Sundays test runs on testnet again, but this time asking people to try finding exploits and weaknesses in the code, and attempt to break a shuffling. There are bounties offered for successful exploit, or just for participation. More details in the coin shuffling testing
thread. The source code is on bitbucket and in the 1.7.4 client package as usual, here is some documentation about how shuffling works
, and also a code review
and discussion with the shuffling paper author.